Gh0stG1rl's feed

Why in like most romance manhwa I read, if they want to feed a person something, they have to use their mouth? Can't they just use their hands? Or do they need to use their tongue or saliva to push something in? Can't they just use their hands?

Do wigs that easy to take off? I've never wore one so I don't know.

And why is it troublesome to wear the wig when she just need to take the potion/pill from her necklace? Is there a need to take it off in the first place?